Small bowel obstruction and mesenteric
ischemia in a 91 year‐old woman
Shantanu
Gaur, HMS III
Gillian Lieberman, M.D.
September 17, 2010
Our patient: history and physical exam
HistoryHistory
2 hours of 10/10 dull, diffuse abdominal pain, worse in her
left lower quadrant (LLQ), with severe nausea. Moved
bowels immediately after dinner; “spitting up”
and has not
moved flatus since then. Denies fevers, chills, vomiting,
diarrhea.
Relevant
PMH/PSH
Relevant
PMH/PSH
Diverticulosis
(last colonoscopy 04/2005), sigmoid resection
for diverticulitis, hysterectomy
(unknown dates)
Physical ExamPhysical Exam
T = 97.9; P = 68; BP = 112/58; RR = 20; O2sat = 99
In distress, writhing in bed. Lower midline and para‐median
scars noted. Abdomen is diffusely distended, tender to
palpation in the LLQ, and tympanic to percussion.
LabsLabs WBC = 14.2; lactate = 2.1
2
Our patient: differential diagnosis for
LLQ abdominal pain
VascularVascular Mesenteric ischemia, abdominal aortic aneurysm, ischemic colitis,
rectus sheath hematoma
InfectiousInfectious Abscess (s/p
surgery), Recurrent diverticulitis, mesenteric adenitis,
pyelonephritis, pancreatitis, appendicitis, cholecystitis
NeoplasticNeoplastic Intra‐
or extra‐luminal tumor
Drugs/toxinsDrugs/toxins C. diff colitis
IatrogenicIatrogenic Adhesions s/p
abdominal surgery
CongenitalCongenital Unlikely
AnatomicAnatomic Small bowel obstruction, strangulated hernia, renal colic, bladder
rupture
TraumaTrauma Traumatic fall with subsequent hematoma/hemorrhage
EndocrineEndocrine Adrenal crisis, hypocalcemia
3
Our patient: paucity of LLQ gas on supine abdominal radiography
4 PACS, BIDMC. Accessed 09/14/2010.
Paucity of gas in the LLQ. Otherwise,
normal gas pattern with no evidence
of dilated loops or
pneumoperitoneum. Incidental left
lower lobe atlectasis.
Paucity of gas in the LLQ. Otherwise,
normal gas pattern with no evidence
of dilated loops or
pneumoperitoneum. Incidental left
lower lobe atlectasis.
Our patient: supine abdominal radiograph.
Our patient: dilated small bowel loops and air‐fluid levels
on CTA abdomen/pelvis
5 PACS, BIDMC. Accessed 09/14/2010.
Dilated loops of fluid‐filled small
bowel with multiple air fluid levels.
Dilated loops of fluid‐filled small
bowel with multiple air fluid levels.
*
*
Our patient: axial CTA abdomen/pelvis.
*
Our patient: transition point on CTA abdomen/pelvis
6 PACS, BIDMC. Accessed 09/14/2010.
Our patient: axial CTA abdomen/pelvis.
A transition point clearly demarcates
dilated and collapsed small bowel.
A transition point clearly demarcates
dilated and collapsed small bowel.
Our patient: fat stranding and mesenteric congestion on CTA abdomen/pelvis
7 PACS, BIDMC. Accessed 09/14/2010.
Our patient: axial CTA abdomen/pelvis.
Fat stranding and prominent
vessels suggest inflammation and
mesenteric congestion.
Fat stranding and prominent
vessels suggest inflammation and
mesenteric congestion.
Our patient: dilated loops of small bowel on coronal
reconstruction of CTA abdomen/pelvis
8 PACS, BIDMC. Accessed 09/14/2010.
Our patient: coronal reconstruction of CTA abdomen/pelvis.
Dilated loops of small bowel seen
in coronal reconstruction correlate
to paucity of gas seen in supine
abdominal radiograph.
Dilated loops of small bowel seen
in coronal reconstruction correlate
to paucity of gas seen in supine
abdominal radiograph.
Our patient: patent SMA on coronal reconstruction of
superior mesenteric artery (SMA)
9 PACS, BIDMC. Accessed 09/14/2010.
Our patient: CTA coronal reconstruction of SMA.
The superior mesenteric artery
appears widely patent without
thrombus. A nasograstric
tube
had been placed in the emergency
room.
The superior mesenteric artery
appears widely patent without
thrombus. A nasograstric
tube
had been placed in the emergency
room.
Small bowel obstruction: relevant anatomy
10
Frank H. Netter, Atlas of Human Anatomy, 3rd
ed. Plate 261
Drake et al. Gray’s Anatomy for Students. 2005. Fig. 4.96.
Small bowel obstruction: epidemiology
20%20%
Percentage of adult general surgery admissions for
abdominal pain with a final diagnosis of mechanical SBO.
70%70%
Percentage of cases of small bowel obstruction caused by
adhesions.
93%93%
Percentage of patients who undergo transperitoneal
surgery
who will develop post‐operative adhesions.
$1.3Bn$1.3Bn
Financial impact of direct patient care owing to adhesion‐
related disorders annually in the US.
11
Bevan, 1984; Menzies
and Ellis, 1990; Attard
and MacLean 2005.
Small bowel obstruction: etiology
Intraluminal
Foreign body
Gallstone
Bezoar
Wormball
Fecal impaction
Intramural
Benign: adenoma, leiomyoma, lipoma,
Crohn’s
disease
Malignant: primary adenocarcinoma,
lymphoma, metastasis
Extrinsic
Adhesions, adjacent mass, hernia,
volvulus, intussusception
12
Small bowel obstruction: regional differences
13
Small bowel obstruction: classification
PartialPartial
No identifiable transition point that demonstrates distal,
collapsed bowel. Patient continues to pass flatus and stool.
CompleteComplete
Transition point clearly separates proximal, dilated bowel
from distal, collapsed bowel.
SimpleSimple
Blood supply to obstructed bowel remains intact.
StrangulatedStrangulated
Blood supply compromised, with signs of bowel ischemia.
14
Small bowel obstruction: treatment algorithm
15
Small bowel obstruction: imaging algorithm
16 Silva et al. 2009
Small bowel obstruction: plain abdominal
radiography
ReliabilityReliability
Diagnostic:
50‐60%
Equivocal:
20‐30%
Nonspecific:
10‐20%
Findings of
high‐grade SBO
Findings of
high‐grade SBO
• Dilated loops of bowel >3cm in diameter or exceeding
50% of the caliber of the largest visible loop of colon• > 3 air‐fluid levels
• Air‐fluid levels wider than 3cm
• Bowel wall thickening >3mm
Without the clinical signs of ischemia
(fever, tachycardia, leukocytosis, focal
abdominal pain), however, surgical
intervention is usually not indicated.
Without the clinical signs of ischemia
(fever, tachycardia, leukocytosis, focal
abdominal pain), however, surgical
intervention is usually not indicated.
17 Silva et al. 2009
Companion patient 1: upright abdominal radiograph
18 Silva et al. 2009
Common findings of SBO on
abdominal radiograph include
multiple air‐fluid levels (arrows),
thickened bowel walls (not seen), and
dilated loops of small bowel
(asterisk). *
Companion patient: upright abdominal radiograph.
Small bowel obstruction: abdominal CT
ReliabilityReliability
Sensitivity:
90‐96%
Specificity:
96%
PPV:
95%
Questions
answered by CT
Questions
answered by CT
• Is the small bowel obstructed?
• What is the severity of the obstruction?
• Where is the transition point?
• Is the SBO strangulated?
Data applies mostly to high‐
grade SBO. Low‐grade SBO
may be more of a “blind
spot”
for CT.
Data applies mostly to high‐
grade SBO. Low‐grade SBO
may be more of a “blind
spot”
for CT.
19
Companion patient 2: SBO on CT abdomen/pelvis
CT criteria for an SBO is dilated
small bowel (> 3cm) proximal
to normal caliber or collapsed
distal loops (arrows).
20 Silva et al. 2009
Is the small bowel obstructed?
Companion patient: axial CT abdomen/pelvis.
Companion patient 3: complete SBO on
CT abdomen/pelvis
A complete obstruction
is one that does
not permit contrast from passing into
distal small bowel (arrowhead). This
patient had an intussusception
(star).
Note the air fluid levels in the proximal
bowel (arrows).
21 Silva et al. 2009
What is the severity of the obstruction?
Companion patient: axial CT abdomen/pelvis.
Companion patient 4: small bowel feces sign on
CT abdomen/pelvis
A
small bowel feces sign (asterisk) is often
indicative of long‐standing, high‐grade
obstruction but has low overall
prevalence. This patient had an SBO
secondary to a post‐operative adhesion
(arrow).
22 Silva et al. 2009
What is the severity of the obstruction?
Companion patient: axial CT abdomen/pelvis.
Companion patient 5: transition point on
CT abdomen/pelvis
The transition point (arrow)
marks a caliber change (>50%
in high‐grade obstruction)
from dilated
(s) to collapsed
(c) small bowel.
23 Silva et al. 2009
Companion patient: axial CT abdomen/pelvis.
Companion patient 6: strangulated SBO on
CT abdomen/pelvis
24 Silva et al. 2009
Companion patient: axial CT abdomen/pelvis.
Obstruction accompanied by intestinal
ischemia is known as strangulation.
Findings of ischemia include gas in the
intrahepatic
portal veins (left, black arrow)
and pneumatosis
coli (right, white arrows).
Obstruction accompanied by intestinal
ischemia is known as strangulation.
Findings of ischemia include gas in the
intrahepatic
portal veins (left, black arrow)
and pneumatosis
coli (right, white arrows).
Our patient: follow‐up
25
• Open laparotomy
with LOA.
• Few adhesions found on initial inspection of the
abdominal wall.
• Adhesion noted in LLQ emerging from adjacent loop of
small bowel that had strangulated the adjacent
mesentery.
• Bowel appeared ischemic and hemorrhagic.
• 40cm small bowel resected
with primary anastomosis.
• 6 day uneventful post‐operative hospital course;
discharged home
Our patient: hemorrhage on histopathology
Courtesy of Brijal
Dave, M.D.
Our patient: mesenteric congestion on histopathology
Courtesy of Brijal
Dave, M.D.
Conclusion
28
Key PointsKey Points
Even without signs of ischemia or necrosis on CT, a high‐
grade small bowel obstruction coupled with clinical
signs of
ischemia should be aggressively treated.
Small bowel obstructions can evolve over the course of
hours. Initial abdominal plain films may not demonstrate an
underlying obstruction.
Mesenteric ischemia and small bowel obstruction can
present simultaneously, as in this case, if the obstruction also
compresses the mesentery.
Acknowledgements
• Ernie Yeh, M.D.
• Leo Tsai, M.D.
• Brijal
Dave, M.D.
• Larry Barbaras, Webmaster
• Gillian Lieberman, M.D.
• Emily Hansen
29
References
30
1.
Attard
JAP, MacLean AR. Adhesive small bowel obstruction: epidemiology, biology and prevention.
Canadian Journal of Surgery 2007;50:291‐300.
2.
Balthazar EJ. CT OF SMALL‐BOWEL OBSTRUCTION. American Journal of Roentgenology
1994;162:255‐
61.
3.
Bevan PG. ADHESIVE OBSTRUCTION. Annals of the Royal College of Surgeons of England 1984;66:164‐
9.
4.
Maglinte
DDT, Kelvin FM, Sandrasegaran
K, et al. Radiology of small bowel obstruction: contemporary
approach and controversies. Abdominal Imaging 2005;30:160‐78.
5.
Menzies
D, Ellis H. INTESTINAL‐OBSTRUCTION FROM ADHESIONS ‐
HOW BIG IS THE PROBLEM. Annals
of the Royal College of Surgeons of England 1990;72:60‐3.
6.
Silva AC, Pimenta
M, Guimaraes
LS. Small Bowel Obstruction: What to Look For. Radiographics
2009;29:423‐U150.
7.
Wiesner
W, Khurana
B, Ji
H, Ros
PR. CT of acute bowel ischemia. Radiology 2003;226:635‐50.
Small bowel obstruction and mesenteric ischemia in a 91 year-old woman
Our patient: history and physical exam
Our patient: differential diagnosis for�LLQ abdominal pain
Our patient: paucity of LLQ gas on supine abdominal radiography
Slide Number 5
Our patient: transition point on CTA abdomen/pelvis
Our patient: fat stranding and mesenteric congestion on CTA abdomen/pelvis
Our patient: dilated loops of small bowel on coronal �reconstruction of CTA abdomen/pelvis
Our patient: patent SMA on coronal reconstruction of �superior mesenteric artery (SMA)
Small bowel obstruction: relevant anatomy
Small bowel obstruction: epidemiology
Small bowel obstruction: etiology
Small bowel obstruction: regional differences
Small bowel obstruction: classification
Small bowel obstruction: treatment algorithm
Small bowel obstruction: imaging algorithm
Small bowel obstruction: plain abdominal radiography
Companion patient 1: upright abdominal radiograph
Small bowel obstruction: abdominal CT
Companion patient 2: SBO on CT abdomen/pelvis
Companion patient 3: complete SBO on �CT abdomen/pelvis
Companion patient 4: small bowel feces sign on �CT abdomen/pelvis
Companion patient 5: transition point on �CT abdomen/pelvis
Companion patient 6: strangulated SBO on �CT abdomen/pelvis
Our patient: follow-up
Our patient: hemorrhage on histopathology
Our patient: mesenteric congestion on histopathology
Conclusion
Acknowledgements
References